int a = 1;
char *b = "please input a number\n";
char *c = "end\n";
enum { A = 1,B = 2,C = 3 };
int main(){
    int i = 0, j = 0, sum = 0;  
    printf("%d %d %d\n", i, j, sum);
    printf("%s", b);
    scanf("%d", &i);
    printf("this is input number i : %d\n", i);
    i = 0;
    while(i < 3){
        for(j = 0 ; j < 2 ;j++){
            sum = sum + 1;
        }
        i++;
    }
    i = i & a;
    sum = sum + 1;
    printf("%d\n", sum);
    printf("%d\n", i);
    printf("%s", c);
    return 0;
}